有机铬的研究进展

铬是动物体必需的微量元素.Cr3+作为葡萄糖耐量因子(GTF)的活性成分强化胰岛素的生理功能,调节三大营养物质的代谢.与无机铬相比,有机铬易被动物体吸收,生物利用率高.大量研究结果表明有机铬在减少动物应激、改善胴体品质、提高母猪繁殖性能等方面有明显作用.     

皖南花母猪生殖系统生长发育的研究

对皖南花母猪生死器官的生长发育进行了测定。结果显示：仔猪出生时卵巢的重量为１２．５～１４．９ｍｇ,卵巢重量吾现指数生长模式,１２０日龄后右侧卵巢重量和体积的生长明显快于左侧。仔猪出生时输卵管长度达到２．３０～２．４９ｃｍ,４５日龄为８．３～８．５ｃｍ,２４０日龄达到２１．３～２１．５ｃｍ,１８０日龄后右侧输卵管外径的生长速度明显快于左侧。子宫的的生长发育与日齿蝗一相关明显。血浆中ＧＨ和Ｔ４激素水平     

夏洛来母牛生殖性能及利用年限观察

对法系纯繁夏洛来母牛生殖性能的统计表明:初情期平均13.0±1.89月龄,性成熟期平均14.62±2.6月龄,始配年龄21.56±1.23月龄,绝情期15岁左右;发情周期平均20.51±8.49d,卵泡出现至排卵结束约39.26±8.28h;妊娠期平均283.91±8.05d;犊牛初生重43.49±6.85kg;产后发情平均71.18±49.25d;产犊间隔平均452.26±124.59d。母牛淘汰年龄平均94.77±40.84月龄,利用年限平均69.94±40.66月龄,终生产犊4.78±2.95头。     

牛活体采集卵母细胞技术研究进展

活体采卵是良种胚胎产业化生产的关键技术,具有生产胚胎成本低、效率高,对供体母畜生产和繁殖性能无不良影响等特点,本文综述了牛活体采卵方法、影响采卵效果因素及存在问题等方面的研究进展,对当前肉牛、奶牛发展具有重要指导意义。     

基因型效应对甘蓝型油菜核不育系组织培养再生植株的影响

采用B5附加物培养基，利用10个隐性核不育系材料的初花期茎段为起始外植体，试验了植株再生能力与基因型之间的关系。结果表明，不同基因型材料之间，其再生植株效率的差异达极显著水平。最高的“SS”不育系可达60．7％，最低的是杂87029不育系，仅为4．7％。     

ITS片段作为轮枝菌DNA条形码的评价研究

以轮枝菌属中的重要植物病原性轮枝菌及其近似种共13种35个菌株为材料,探讨ITS片段作为轮枝菌DNA条形码的可行性。结果表明,ITS 成功区分了研究涉及的10个种,其 PCR 扩增和测序成功率为97.1%,序列鉴定成功率为94.5%,但对个别亲缘关系较近种的物种鉴别能力较弱。     

Nesting ecology of Ferruginous Duck Aythya nyroca in north-eastern Algeria

The status of waterbirds breeding in protected areas in North Africa needs constant monitoring because of a naturally fluctuating environment and permissive attitudes towards illegal activities likely to negatively affect population dynamics of threatened species. We present the results of a study conducted at a protected site, Lake Tonga, north-eastern Algeria, on a breeding population of Ferruginous Duck Aythya nyroca, a Near-Threatened duck subjected to considerable pressure from egg-pilfering and illegal hunting. Two distinct habitats within the lake were used by Ferruginous Duck: an Alder carr (Alnus glutinosa) and floating islets across the lake. The mean clutch size was 9.51±1.84 eggs (N = 51 clutches) with hatching rate of 80.7% for successful clutches. Breeding success was low (37%) with predation (33%) and clutch desertion (17%) accounting for the majority of failed nests. The probabilities of nest failure and nest desertion increased with a delayed onset of egg laying. Predation was not significantly associated with egg laying date and vegetation cover, but late breeders nesting in dense vegetation seemed to suffer less predation. Conspecific brood parasitism was positively associated with nest size, whereas interspecific brood parasitism was marginally associated with water depth. We discuss different hypotheses concerning nest desertion, and argue that illegal hunting and disturbance may best explain why birds desert their nests.     

Reproductive performance of camels (Camelus dromedarius) under pastoral management and its influence on herd development

Camels (Camelus dromedarius) produce milk and offspring and provide transport in pastoral husbandry systems in the Afro-Asian dryland belt. The aim of the present study was to investigate the reproductive performance of camels kept under pastoral management in northern Kenya. Using the Progeny History surveying technique, data were collected from 471, 287 and 416 adult Rendille, Gabra and Somali female camels including data on 1506, 789 and 1206 parturitions, respectively. Surveys took place from January to December 1995, but data refer to the 15-year production period preceding the survey. Age at first calving (AFC) was 58.4±1.0 months (LSMeans±S.E.), 63.0±1.1 months and 68.4±1.3 months for the Somali, Rendille and Gabra camels, respectively.The mean calving interval was similar for all three populations with 27.3±0.6 months (LSMeans±S.E.) for Rendille camels, 28.0±0.6 months for Gabra (n=500) and 28.4±0.6 months for Somali camels. The annual calving rate varied between 33% and 46% in the Somali, 19% and 44% in the Gabra and 8% and 86% in the Rendille camel population. Calf mortality rate averaged 25%, 22% and 27% in Rendille, Gabra and Somali camel calves, respectively, and showed highest variation between the years in the Rendille system (5% to 60%).The number of adult breeding females increased by about 20% over a simulation period of 10 years using the status quo reproductive parameters and by about 70% with improved AFC and CI (excluding AFC>78 months and CI>36 months). The results reveal the usual and unusual variation in the reproductive parameters over different years and in the different systems. It is concluded that eliminating unusual variation is a promising way to enhance herd development and reduce risk in the production systems.     

亚丁牦牛繁殖性能调查

[目的]为了了解亚丁牦牛品种的繁殖性能,更加深入了解其资源特性,为后续制定选育标准和提高繁殖存活率提供理论依据。[方法]调查了亚丁牦牛主产区养殖亚丁牦牛的2016—2018年存栏情况,统计亚丁牦牛繁殖存活率。[结果]结果显示亚丁牦牛繁殖存活率达到61.78%,表明亚丁牦牛具有繁殖性能高的特点。     

Squamous cell carcinoma of the equine stomach

Summary

Both clinical and pathological features of seven horses suffering from a squamous cell carcinoma of the stomach are presented. The main complaints in the horses, aged six years or more, were loss both of weight and of condition. Metastases had often developed.

The diagnostic difficulties and possibilities are discussed.